Molding-flask for dentists&#39; use



G. E. TERRANOVA. MOLDING FLASK FOR DENTISTS' USE.

APPLICATIO N FILED OCT. 28, 1920.

1,372,209. Patented Mar. 22,1921.

UNITED STATES PATENT OFFICE.

MOLDING-FLASK FOR DENTISTS USE.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application filed October 28, 1920. Serial No. 420,079.

To all whom may concern:

Be it known that I, Grusnrrn E. TERRA- NOVA, a subject of the King of Italy, residing at New Haven, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in MoldingFlasks for Dentists Use; and I do hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this application, and represent, in-

Figure 1, a top or plan view of a flask for dentists use constructed in accordance with my invention.

Fig. 2, a side view of one of the members illustrating the model suspended therein.

Fig. 3, a perspective view of the two members, each containing part of a mold with the model removed.

Fig. 4, a perspective view of one of the flask members detached.

Fig. 5, a perspective view of one of the plates detached.

This invention relates to an improvement in molding flasks for dentists use such as are employed in producing metal dies for forming gold crowns. Molds are usually formed in a plaster of Paris composition and this mold must be cut in two in order to remove the model. The object of this invention is to provide a two-part flask in which the mold is formed and which, when separated, will divide the mold. Another object of the invention is to provide for supporting the model while forming the mold, and the invention consists in the construction and arrangement of parts as hereinafter described and particularly recited in the claims.

In carrying out my invention I employ two semi-cylindrical tapered flask members 10 and 11, which together form a round flask smaller at its upper end than at its lower end. Applied to the edges of the members 10 and 11 are plates 12 and 13 formed with outwardly-turned flanges 14 which fit over the edges of the flask members. These plates are cut away at the center, leaving a narrow base 15 and they are each formed with a semi-circular vertical channel 16 and 17. In use, a plate is applied to each flask member and the two members brought together and held by a split spring ring 18. The model 19 is formed in the usual way from a plaster composition and is gripped between spring fingers 20 and 21 which are connected with an arm 22 which is adapted to extend down through the openings formed by the grooves 16 and 17 so as to properly locate the model die in the flask. The flask is then filled with plastic composition commonly employed by dentists in molding, and when the mold is set the spring ring 18 is removed and the two parts separated by fore ing a sharp edge between the two plates, the plates 12 and 13 forming an edge on which the central portion of the mold will break. The model die is then readily removed, the two parts of the flasks returned to their former position and secured by the spring ring 18 and the metal die is cast into the pattern formed in the flask. To remove the mold, the flanges are separated from the flask members which releases the mold without breaking so that it may be used again for reproduction of the die for which it was formed.

To remove the molds from the flasks the plates 12 and 13 are removed leaving the molds free to slip out of both of the flasks whichwill readily yield for this purpose.

I claim:

1. A flask for dentists use comprising two semi-cylindrical tapered members combined with plates detachably connected with the edges of said members.

2. A flask for dentists use comprising two semi-cylindrical tapered members combined with plates adapted to be applied to the edges of said members, said plates formed in adjacent faces with vertical grooves.

3. A flask for dentists use comprising two semi-cylindrical tapered members combined with plates adapted to be applied to the edges of said members, said plates formed in ad jaeent faces with vertical grooves, and a model holder formed with gripping fingers and an arm adapted to extend into said grooves.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

GIUSEPPE E. TERRANQVA.

Witnesses:

FRANCIS RossI, W. An'romo Clinic. 

